Bobby didn't exactly 'know it' but she'd let it slide. Arguing for arguments sake was not what she was trying to accomplish here. She was trying to get her feelings across so he'd understand a little better why she was about to take a break from their relationship, even if just for a few days.
"It had to do with stress relief, and I wouldn't have been naked." She rolled her eyes. "And I'm pretty sure this has nothing to do with Penny."